How do I appear more feminine?

I'm a girl, but I've been growing up around boys... and I guess, I've sorta gotten to become like them.. I mean, the hands in the pockets things, the punching, the not standing straight like a swan... I want it to change.. I mean, I attract guys, but... I attract them like a FRIEND. It's not the whole deal about attracting guys, but it's... when I hang out with girl friends, they're so feminine and perky and... just so GREAT, and I always feel like a MAN... Help?